textproduct: Quad Cities

KEY MESSAGES

- A prolonged period of wet weather will be seen through late week in the form of three rounds of heavy rain. In between each round, spotty showers and potentially drizzle will be seen.

- Given the long duration of the rain, rises on area rivers will occur. The probability of a flood watch being needed at some point over the next 72 hours is around 30 percent.

- A drier and cooler weather pattern will set up this weekend and into early next week.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 201 PM CDT Tue Sep 29 2026

After a pleasantly warm fall day, rain showers will develop tonight and evolve into a widespread rain by sunrise Wednesday. The rain will taper off to more spotty showers and potentially drizzle for Wednesday afternoon.

Prime time for the first round of heavy rain looks to occur between midnight and noon Wednesday. Any thunderstorms will be isolated so rain rates look to be light to moderate with periods of heavy rain. HREF probabilities of exceeding 0.25 inches/hour are at 30-40%. The axis of this round of heavy rain looks to lie between Cedar Rapids and the Quad Cities.

LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/

Issued at 201 PM CDT Tue Sep 29 2026

Wednesday night through Friday Assessment...very high (>90%) confidence of widespread heavy rain

Round 2 of heavy rain will occur Wednesday night into Thursday morning. The probabilities of heavy rain are the highest during this time frame as PWATS are just over 2 inches and the overall forcing will be enhanced with the passage of a weak surface low.

The axis of the heaviest rain looks to run from Cedar Rapids up to Dubuque; thus there will be some overlap between round 1 and 2. Like the previous night the probability of rainfall rates exceeding 0.25 inches/hour is 30-40 percent. Thus this will be another long period of light to moderate rainfall with periods of heavy rain. Thunderstorms will be possible but are still expected to remain isolated to low end scattered (20-30%).

Another period of spotty showers and drizzle looks to occur Thursday afternoon before round 3 begins late Thursday afternoon into Thursday night.

Unlike the previous two rounds of heavy rain, this round will be further to the south and east. Right now the rough axis looks to be from roughly Keokuk, IA to Peru, IL. Given the southward trend with the heavy rain, the possibility does exist that the axis of round 3 could be further to the south and east. Thunderstorms will be possible but will remain isolated to low end scattered (20-30%).

Like the previous two round of heavy rain, the probability of rainfall rates exceeding 0.25 inches/hour are 30-40%.

By late Thursday night and into Friday morning, rain will end from northwest to southeast. Friday afternoon looks to be cool with temperatures only in the 60s.

Friday night through Tuesday Assessment...medium to high confidence (50-70%) of dry and cool conditions

Starting this weekend and continuing into the first half of next week cool fall-like temperatures are expected. The global models have been advertising this scenario for over a week but have slowly shifted the brunt of the coolest air to the eastern Great Lakes and New England.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 615 PM CDT Tue Sep 29 2026

A round of rain/showers and possibly isolated storms is expected tonight through early Wednesday afternoon. This will be largely with VFR to MVFR conditions, with IFR possible. Guidance is wanting to bring in IFR ceilings overnight and throughout the day on Wednesday, particularly at KCID and KDBQ. Confidence is somewhat low on this, as currently much of the guidance is verifying too expansive/overdone with low conditions to our west. I did maintain the IFR ceilings at KCID and KDBQ, but given the guidance trends opted to push back these until Wednesday morning. There is a signal for improvement back to VFR at KBRL and KMLI later Wednesday afternoon as the initial round of rain diminishes and low level flow veers from S/SW offering potential for some lifting ceilings.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.